In the suburbs, the nouveau riche industrialist or merchant could reinvent themselves away from their working environment, in the style of the landed gentry who traditionally had seats in the countryside. On the rural fringe of the town they could use their wealth to cultivate social prestige by building grand houses and creating ornate demesnes. Quite a number of these properties were funded from the large profits that arose from the increased banking turnover during the first half of the century. The Batt family were able to rebuild Purdysburn, the Herons built Maryfield, and the Houstons, Orangefield, all because of their banking fortunes. Trade and alcohol permitted the Turnlys to build Richmond Lodge and the Dunville family to move to Redburn. Ballywalter Park was designed by Charles Lanyon around 1846 for Andrew Mulholland, the proprietor of York Street flax spinning mill and sometime Mayor of Belfast. The Ewarts bought Glenmachan, the Combes and later the Perries were both involved in the construction of Ormiston.

Ballymacarrett's only residents of note at the end of the eighteenth century were the Pottingers who had built a large three-storey house called Mount Pottinger, later known just as the Mount. Having experienced some financial difficulties, the family was forced to sell Ballymacarrett to Barry Yelverton, lord chief baron and later Lord Avonmore. He began planning and building a number of streets in Ballymacarrett. The 1st Marquis of Donegall was not keen to see another town beyond his influence being on the other side of the river so purchased Ballymacarrett for £20,000. But this area was less influenced by the Donegalls than by the development of a number of industries including a pottery and a vitriol works. Rows of houses were provided for the workers at the Lagan Foundry owned by Edward Stainton and Victor Coates. These houses formed clusters or the little 'villages' of Short Strand, Gooseberry Corner, and Bridge End. Between them were the houses and demesnes owned or leased by professional men and merchants. The old demesne of Mount Pottinger was remodelled during the 1840s as a square of substantial gentlemen's residences complete with spacious gardens. But as the number of industrial concerns increased in the area, the need for housing grew, particularly with the development of shipbuilding on the County Down shore. With this increase of working class housing, the commercial gentry and professional men moved out of the area towards Strandtown and Sydenham.

Strandtown became a popular residential location by the middle of the nineteenth century. McComb's Guide to Belfast described it as a picturesque and healthy locality gently ascending the slope about a mile from the eastern suburbs. Connsbrook House, which appears on the 1834 Ordnance Survey map of East Belfast, was one of a number of properties inhabited by people who had previously lived in the centre of the town. Connsbrook House's first known resident was a wholesale general merchant called John Martin who had moved from Anne Street. John Martin later became a shipowner. A later occupant was a merchant tailor, Thomas Spackman, who had previously lived in High Street. Spackman was an entrepreneur and had a claim on the invention of the patent sewing machine. The house was described in an advertisement in the Northern Whig, 3 February 1869, as having two reception rooms, six bedrooms, servants' apartments, stables, coach and other office-houses. There was also a four-acre ornamental garden and a large kitchen garden stocked with fruit trees. In a painting of Connsbrook House in the collection of the Belfast Harbour Commissioners, the Queen's Quay to Holywood railway is visible and the glass works are also depicted.

Also in the collection of paintings of the Belfast Harbour Commissioners can be found 'View of Sydenham, Belmont and Glenmachan' by J.H. Connop, which was completed in 1864. This shows a number of mansion and villa properties that had been constructed for Belfast's merchant princes. The island in the foreground of the painting is the East Twin Island. Along the shore the Holywood and Bangor railway line is shown, with Sydenham station on the right beside the reclaimed land. Beyond Strandtown is shown an area known as the Knocknagoney Heights. Houses in this area were more elevated, had better views over the Lough, and were considered to be in healthy surroundings as the residents could benefit from the sea breezes. The owners of houses here were among the wealthiest men in Belfast as few others would have had the time and money to travel in and out to Knocknagoney. Some magnificent mansions were built in this locality, several on the road to Holywood and others on the southern part of Knocknagoney around Dundonald.

One of the largest, most mature and private demesnes in the area was Belmont (previously Bell Mount) which had been built in the 1830s for the solicitor Alexander Montgomery. The estate was sold to the tobacco merchant and politician, Sir Thomas McClure. Belmont can be seen in the middle background of the Connop painting. McClure leased some land in the 1850s to the celebrated architect Thomas Jackson who designed many of the mansions in the locality. His first house was Glenmachan in which he himself lived for a number of years before selling it to Sir William Ewart, a leading linen manufacturer. Bordering the Belmont estate, another mansion, Netherleigh, was constructed for the Robertson family in 1875 and bought by another linen family, the Hall-Thompsons. Nearby Stormont (previously 'Mount Pleasant') became the property of the Cleland family. The Clelands owned a huge estate in East Belfast that stretched from Orangefield through Bloomfield to Dundonald. They had enlarged and improved the Georgian house at Storm Mount during the early 1830s, but their immense wealth allowed the Clelands to redevelop once again. Stormont Castle was designed in a Scottish baronial style by Thomas Turner and built in 1858. Another typical property was Bunker Hill. Its tenant in 1850 was Chevalier Gustavus Heyn, who owned the Ulster Steamship Company. He had originally lived in Henry Street in the town, moving first to Strandtown House and then to Bunker Hill. He did not remain there and other entrepreneurial men rented or bought the property. In 1863 six acres of its demesne were sold off for building new houses.

The development of gentlemen's residences on the northern slopes of Knocknagoney Heights towards Holywood was due to the affluence and prosperity of some of Belfast's leading families who wanted to play at being landed gentry. Villas at Holywood tended to be of a substantial size; most were two storey with five or sometimes six bays. The owners added gate lodges to the ground and had their large demesnes landscaped. These houses also required more servants than some of the villas in Strandtown and it was fashionable to employ English butlers, cooks, and housekeepers. The Dunville family was typical of the residents in this area. The distiller John Dunville and his son William were responsible for the redevelopment of Richmond Lodge. John's great nephew, Robert Grimshaw Dunville, owned another neighbouring fine villa, Redburn. The plan of Richmond Lodge shows a long driveway to the house, ensuring complete privacy, and extensive grounds. The grounds at Richmond were so large that Captain R.L. (Bobby) Dunville established a private zoo there during the 1920s.

As the century progressed, great changes were taking place throughout East Belfast. The success of the shipbuilding industry encouraged other industrial ventures: foundries, rope and engineerings works. People flocked to the area to provide the workforce, and a building boom resulted in rows of terraced housing in Ballymacarrett, an area that gradually became almost solidly working class. Even the Mount had lost prestige, the captains of industry preferring to move further out. New roads were being created for the horse omnibus and later tramcars to ferry passengers from Belfast to the growing suburbs. Connsbrook House became surrounded by streets, including Connsbrook Avenue, and a number of detached and semi-detached houses were built on its former demesne. By the end of the nineteenth century, Belmont, along with Strandtown and Knock, was not just a retreat for the affluent, but a flourishing, expanding community. This may have been the factor that influenced the trustees of Henry Campbell's estate when they decided to buy Belmont House. As a sign of changing times, Campbell College was built around Belmont House and the house then demolished.